Even I could not find the reason. It looks like to me that macro in 2007 is not overwriting the previously copied content and is creating a seperate space for the newly copied data on RAM / Cache memory.

I have come to this conclusion since the macro starts very fast; however, when it comes to row 100 it becomes little slow and at rows 800-900 it works painfully slow.

Have you ever heard of this situation or come across this situtation in office 2007 where Macro does not overwrite the previous content? if yes, what is the solution for this. Thanks.